1. Field of the Invention
The present invention relates to a hydraulic shock absorber suitably used in a motorcycle front fork or the like.
2. Description of the Related Art
There are hydraulic shock absorbers for a motorcycle front fork or the like, such as the hydraulic shock absorber described in Japanese Patent Application Laid-open No. 2004-44669, in which a wheel side inner tube is slidably inserted into a vehicle body side outer tube, a partition wall member is provided on an inner circumference of the inner tube, an operating oil chamber is defined below the partition wall member and an oil reservoir chamber is defined above the partition wall member, a piston rod mounted on the outer tube side is penetrated through the partition wall member and inserted into the operating oil chamber, a piston that slidably moves in the operating oil chamber is provided on a tip portion of the piston rod, the operating oil chamber is partitioned by the piston on both sides of the piston into a rod side oil chamber that houses the piston rod and a piston side oil chamber that does not house the piston rod, a suspension spring is arranged in the piston side oil chamber inside the inner tube, and the hydraulic shock absorber has a spring load adjusting device that adjusts a spring load of the suspension spring.
In the hydraulic shock absorber described above, the spring load adjusting device screws an adjuster to a cap fixed to an upper end portion of the outer tube and fixes the piston rod to a lower end portion of the adjuster inserted into the oil reservoir chamber, and the piston on the tip portion of the piston rod pressurizes the suspension spring via a spring collar from a lower end surface facing the piston side oil chamber. By screwingly moving the adjuster, the piston rod and the piston are moved up and down relative to the outer tube. The spring load of the suspension spring is adjusted by this up-and-down motion.
In addition, with the hydraulic shock absorber described in Japanese Patent Application Laid-open No. 2004-44669, a rebound spring is arranged around the piston rod in the rod side oil chamber inside the inner tube, a maximum tension stroke upon maximum tension of the outer tube and the inner tube is restricted by the rebound spring, which is back-supported by the piston provided on the piston rod, as the rebound spring abuts the partition wall member provided in the inner tube and, as a result, total fully-stretched lengths of the outer tube and the inner tube are regulated.
Patent Document: Japanese Patent Application Laid-open No. 2004-44669